Cultivation practices with various mulching materials to regulate chlorophyll fluorescence, cuticular wax, and rapeseed productivity under semi-arid regions

Water shortage continues to threaten the productivity of rapeseed in China dry-land planting system of china. There is an urgent need to build up efficient water saving management practices. Therefore, the field experiment was conducted by using a randomized complete black design with three replications under two cultivation practices: RF: ridge-furrow rainwater collection system, and CP: conventional flat planting; with four different mulching materials, such as plastic film mulching (PM); biodegradable film mulching (BM); straw mulch (SM) and no mulch (NM) were used in this study. We found that under different mulching materials, cultivation practices have a considerable effect on rainwater collection and improvement of soil water storage. Under the RF-PM and RF-BM treatments can considerably improve rapeseed photosynthesis (Pn, 54.1%), ETR (50.9%), ΦpsII (38.4%), the maximum quantum efficiency (Fv/Fm, 8.9%), Fv/Fo (25.7%) and Fv/Fm′ (26.1%), at the bolting, flowering and seed filling stage. These enhancements were attributed to the significant increase in soil water storage, total chlorophyll ab (59.4%), and chlorophyll stability index, as well as the decrease in evapotranspiration (ET, 3.9%), all of which improved water use efficiency (WUE, 28.0%), cuticular wax composition, grain yield (25.2%) and economic return (10459 Yuan ha−1) of rapeseed. These results showed that the RF planting practice using PM mulching materials is the best water-saving management practice to improve rapeseed photosynthesis, fluorescence, cuticular wax composition, WUE, and productivity in dry-land agricultural systems.